Touched my battery posts together. Now what. ?

roscoe

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Oct 30, 2002
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Interesting.
How did you get the posts to touch?
Mine are securely attached to the battery, 11" apart. LOL :)

Probably fried the voltage rectifier.

First sign of damage is that the tach doesn't work, or is misreading.

Second sign is that the motor is no longer outputting a charge to keep the battery inflated, I mean charged.

Start engine and put leads of volt meter on the battery terminals.
If it is not reading over13v at a fast idle., rectifier is damaged.
 
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HA. ya mine are too.. it takes talent trust me.. touched a wrench to them tightening one of the nuts on battery. not good. .

Would that cause it to run so rough?

i'll put my meter to it tomorrow and see what it reads. appreciate it.
 
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roscoe

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Typically, if you hook the battery up backwards, you will fry the rectifier/regulator.

I would think if you just shorted out the battery terminals, it would have no effect on the motor, but who knows.

Checking the charging output is a good place to start, as you want to make sure it is charging before heading out too far on the water.

And yes, a bad rectifier can cause poor running, not always, but sometimes.

Keep us updated.
 

Texasmark

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Alternators generate AC voltage that is rectified to DC by the Rectifier/regulator module. In rectifying the voltage a pair of diodes are used for each pole of the alternator output....one supplying current to the + output and the other, inversely wired (anode grounded), supplying the return path to the alternator winding. If you put - on the + lead and in doing so, close the loop so current can flow in the reverse direction, there is nothing to limit the current in the circuit and the - diode will melt internally causing a short circuit and if sustained long enough, something is going to melt.

The trigger coil (Stator) shouldn't care as it's a piece of wire. The Capacitor Discharge Modules have to have a holding diode at the input to the capacitor so that the charge doesn't bleed off between "humps" of the rectified AC input. Reversing that input "shouldn't" matter unless a reverse transient of sufficient amplitude were applied to the diode, which I doubt could happen. Trigger circuits in the CDM have/should have adequate protection.

Mercury tach signals are rectified sine waves and are the grey wire coming off the Rect-Reg module.

If the reverse were to burn out the charging coils, it shouldn't affect the trigger coils (under the flywheel....Stator) as they are separate circuits. However, if all the wires are bundled as they come from the Stator, and the short lasts long enough, the insulation could melt and the wiring bundle could experience short circuits between wires and that could affect performance.

Couse with no Alternator and having experienced a short circuit, bleading off battery power, what was your battery voltage when your engine was running rough after the incident? If low, recharge it and try again........with your Reg-Rect. plug removed!
 
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Came home today and started her up. The meter read 12.4 before starting and while running (very rough) it never got above 12.4.. would bounce between 12.3 and 12.4.
 

jimmbo

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At what rpm were you checking the Voltage at? You could also put an Over the cable Ammeter to see if current is flowing into the Battery
 
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i dont have a tach on the boat. but i upped the idle to half throttle or more.. it was revving high. left it that way for about 10 seconds or more than backed it off and shut it down.. if i need to run it longer or higher rpms i can.
 

Texasmark

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i dont have a tach on the boat. but i upped the idle to half throttle or more.. it was revving high. left it that way for about 10 seconds or more than backed it off and shut it down.. if i need to run it longer or higher rpms i can.

Your rect-regulator module is shot. Details furnished if you want. Forget the ammeter, not necessary on this one.
 
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Well im at a loss now. so i replaced the regulator and now have 15.3 volts on my meter running high rpm. but it was still running same way. rough, spitty. but started right up. so i replaced the cdi. it started right up, ran 90%. was only sputtering a little, but seemed to be running at lower rpm than normal. left it that way for about 5 minutes. revved it a few times, shut it off.. tried restarting and it wont start without going full throttle and than when it starts it sputters and wants to die. saturday this thing was running like a beast. now its sputtery and doesnt want to start. im going to put old cdi back on and see if it atleast still fires right up, but run rough. see if that changes anything. thought maybe i got a bad cdi. but why would i have to go full throttle to get it to start now.. so odd.. its seems the timing is off.. all cylinders have fire. saturday this thing started right when you touched the key.
 
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Texasmark

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Get an automotive timing light, battery powered is the most convenient, and clamp it onto your spark plug wires. It will tell you a lot about where to start looking for your remaining problem. If you get consistent fire on all cylinders, even when acting up, go after fuel related problems, especially clogged fuel filter, internal fuel lines degrading, fuel line between the engine and the tank. If all those lines are original, time to replace them.

The 15.3 volts tells me that you don't have a regulator in your rectifier module as they usually limit out at about 14.5 at high RPMs. No biggie per se, just could cause old style batteries to boil out water, requiring replacement and associated corrosion on and around the battery. Don't know how newly developed batteries handle over voltage for long periods of time.....if you do a lot of long range running.
 
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interesting.. great information.. i will research the regulator. my battery is '18. I did just replace all fuel lines, fuel filters and fuel pump a couple weeks ago... its been running great since than but maybe thats the problem im having and not electrical.. may run a fuel pump test if need be. but this all started after touching battery posts so thats why i question electrical before fuel but im all for eliminating possible issues.
 

JimS123

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85 60hp mercury .. So ya like a rookie i touched my battery posts together and now my very smooth running engine is now running rough. See video link. What did i fry.? Any suggestions are appreciated. I checked and all 3 cylinders have spark.

https://www.youtube.com/watch?v=kBk4...ature=youtu.be

Funny thing, last year I did the same thing. You'd think after 50+ years owning and maintaining a boat it wouldn't have happened. In my defense, though, the battery is in the back of a compartment, it requires you to stand on your head to attach the battery cables, and I used a wrench that was too long for the job.

Nevertheless, I only noticed it when my Mercury VesselView sounded a warning that the battery voltage was low. Naturally, checked the screen and at 12.2 volts it was obviously not charging. Turned out I blew a fuse.

In any event, the motor ran perfectly throughout the ordeal. I would guess that your error shorted something out. review the Owner's Manual and look for the fuse block. Check and replace as necessary. Also, charge the battery to 100% before you run it again.
 

Texasmark

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Things happen on fuel problem surfacing during an electrical repair, or vice versa.....no exact timing for things to occur.

The boat I bought last summer was a perfect example. I was off chasing this and that....recorded herein......just to find out my problem was a clogged fuel filter!!!!! I don't know how many times I looked it as when you lift the bonnet, (engine cover....British term for Qboy....grin) and looked at the uncovered engine the awfully dirty looking white filter on a Phantom Black back ground just stared at me.....but I never had a fuel filter go bad, thought had entered my mind, but I didn't have a replacement handy so I just just blew it off.....big mistake. But all the time and money I spent is done and doesn't have to be done later and I know what I bought which in itself is worth the time and effort.

Now, the reason for the clogging was little brown chips of crud which I also found on my on my 90 hp at 10 years of age and it came from the fuel line between the engine and fuel tank....Mercury OEM line and bulb and appeared to be the 17 year old original. Ethanol didn't have anything to do with it as the boat had only been run on 91 octane gasoline by me and the PO with Mercury brand #1 Snake Oil in the gas.

Edit: If you do change the filter, and I would as they are cheap and eliminates that item as the smoking gun, cut it open and tell us what you find inside.
 
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I ran some ohm tests on my trigger and stator. I dont have a DVA tester so forgive my archaic troubleshooting.

The 3 trigger wires (brown, white, purple) were tested to the white/black trigger wire and the stator wires were tested to ground.

all wires coming from trigger are at 1208 +/- ohms.

The red coming from stator was at 140.6

The blue coming from stator was 5950.

Seems (from what ive read on the internet) the trigger seems ok but the stators blue wire ohms are too high..

Can anyone confirm this for me please.?

FYI i came out today and had no spark. none. would not start at all. My issue seems progressive.
 
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Here to update my post .. The cdi i purchased was faulty. stator and trigger were fine. so ended up replacing voltage regulator, spark plugs and cdi. now boat is running smooth.. caught some great bass this weekend. purchased voltage regulator part 816770, but i still see my voltage going above 15 on my finders as im running.. is that normal. ?
 

jimmbo

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With an Unregulated System it is normal to go even a bit higher. Unless you spend hrs nonstop at WOT, there is nothing to worry about. But do check the Electrolyte Level in the Battery Regularly, Also never use an AGM, or Sealed Maintenance-Free Battery with you motor, only a Wet-Cell Battery
 
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Excellent information.. What part will give me a regulated system.? is there a different part number i should be looking at? i bought oem. even bought an aftermarket one. both said they were regulator/rectifier. ive been looking at buying an agm battery so id rather have it working correctly.. or is that not even an option for my older motor.. ?
 

The Force power

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Even when a Rectifier is regulated, it still keeps producing voltage (output into the battery)
Over a long period of running after the battery is charged, the water in the battery will start to boil-off.
That's why you HAVE TO have a serviceable battery (to add distilled water) & NO OTHER battery
 

Faztbullet

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Jump over on the Ama*** site and get yourself a $30 5 wire voltage rect/reg and install... no more problems.
 
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